Certain road vehicles may be driven by an internal combustion engine and/or an electric machine. An electric machine, for example, may be used to drive a vehicle at low speeds. An internal combustion engine and the electric machine may be used to drive the vehicle at high speeds. If the internal combustion engine and electric machine are arranged along a common driveline so as to share a common input shaft to a transmission, a clutch may be used to isolate the internal combustion engine from the electric machine. A clutch may also be used to isolate the internal combustion engine and electric machine from the transmission. Certain clutch control strategies may ensure a smooth transition from one source of motive power to another.